from django import forms
class BootStrapModelForm(forms.ModelForm):
    def __init__(self,*args,**kwargs):
        super().__init__(*args,**kwargs)
        #循环所有插件，给每个字段设置插件
        for name,field in self.fields.items():
            #字段有属性，保留原来的属性，没有属性才增加
            if field.widget.attrs:
                field.widget.attrs["class"]="form-control"
                field.widget.attrs["placeholder"]=field.label
            else:
                field.widget.attrs={'class':'form-control',
                                "placeholder":field.label}
